Poor service

Since the 29 September 2023, I am waiting for the replacement of my Chain that was ******. I logged a complaint early to get the claim finalised. The claim was finalised and approved to Diamond Jewellery International. To date, they won't reply to my emails or return my call I have been calling them on ***. I have emailed: *** but have not even received an acknowledgment from them. Please can someone sort this out as this has been one of the worst services I have received.